Making sense of breathing, VO2max and lung capacity

Rowers take pride in the fact that some of the highest scores for VO_2max (maximal aerobic capacity, or, how efficient the lungs are at taking in and delivering the most oxygen possible to working muscles) ever recorded came from elite rowers.

But, how important is breathing to a sport like rowing anyway? Is there anything rowers could be doing differently to improve their performance by simply breathing ‘better’?

World Rowing talked with Mati Arend, a physiotherapist at Estonia’s Tartu University Hospital, to answer these and more questions about breathing and rowing.

Anatomy of a breath
“There are many inspiratory muscles [that help bring air into the lungs], but the main one is the diaphragm” explains Arend, who formerly raced for Estonia and is currently completing a PhD in Movement Sciences. “Neck muscles are called accessory inspiratory muscles, which work more during heavy breathing – for example during maximal rowing.”

The seated posture of rowers, however, adds a challenge to this system. “The cramped up position at the start of the catch affects a rower’s ability to use the diaphragm optimally,” Arend says. This results in an even greater reliance on the accessory muscles.

“People usually think that breathing is mainly regulated by the autonomic nervous system,” says Arend, “and therefore we can’t do anything more about it.” But, this is not the case, he claims, pointing out that the diaphragm and other inspiratory muscles can in fact be trained to become stronger.

Breathing stronger
“Regular inspiratory muscle training has shown to improve endurance performance in rowers, cyclists, runners and swimmers,” Arend explains. “It has also shown to help in the recovery after competition – so you are better before your next race.”

Although you can’t exactly flex them in the mirror to check out improvements, inspiratory muscles get stronger the same way as other skeletal muscles. “They follow the same rules of training,” says Arend. He uses a device in his research to undertake inspiratory pressure threshold loading, or more simply, forcing the breathing muscles to work harder to take a breath.

“It just adds resistance to breathing via a spring loaded valve. Your muscles need to apply enough force to open that valve.” As with any strength gains, it takes a few weeks of training to see improvements.

Lung capacity
While improving the efficiency of your lungs may seem like a marginal gain, the role of lung capacity and VO_2max in particular might seem as more important or at least more familiar measures of potential.

Lung capacity is essentially the total volume of air that lungs can bring in. Although US swimmer, Michael Phelps is rumoured to possess a lung capacity of around 12 litres, British rower and three-time Olympic gold medalist, Pete Reed, seems to hold the official honours of largest ever recorded lung capacity (11.68 litres). This is far above the average of around 6 litres (males) and 4.7 litres (females).

While lung capacity plays an important role in providing more oxygen to the body and increasing VO_2max, there is still hope for those with smaller capacity says Arend. “As the cardiorespiratory system can be improved significantly with training,” he says, “slightly smaller lung capacity is not directly a limiting factor and can be compensated for to have a similar amount of oxygen delivery to the muscles.”

VO_2max
Rowers also rank high when it comes to VO_2max. But here it isn’t so much about a rower’s absolute score when it comes to winning at the elite level, explains Arend. “It is an important measure as it can be viewed as a predictor of how much potential a rower has. “At the elite level there is some variation and the winner probably does not have the highest VO_2max.”

Arend compares the potential of lung capacity and VO_2max to cars: “If you have a two litre engine available and you do not know how to increase its efficiency, then you will always lose to a specialist who works with a 1.6 litre engine and knows how to force the engine to higher horse power.”

“If you want to predict performance at the elite level,” Arend says, “you had better choose some other parameter.”

One possible exception to this is for lightweight rowers, where Arend concedes VO_2max has a “higher correlation to performance than in heavyweights.” Here again though, he points out that there are better parameters for performance prediction such as how long a rower can sustain his or her speed at VO_2max intensity.

Breathing easy
There is also the consideration of a rower’s breathing rhythm. A simple online search for this will result in no shortage of advice. The Concept2 website offers a clear and practical description, pointing out that as the intensity of rowing increases, rowers will generally begin to take two breaths instead of just one per stroke:

“During high intensity rowing (two breaths) – Exhale as you finish the drive,” the website describes. “During the recovery, inhale, then exhale quickly. Inhale again just before the catch.”

The timing at both ends of the stroke are not simply arbitrary. The breath in before the catch creates an increase in intraabdominal pressure, which in turn improves power application on the drive. “More intraabdominal pressure at the start of the catch gives you better stability of the spine,” Arend says. “Exhaling at the end of the stroke is where we use our abdominal muscles anyway and abdominal muscles are involved in exhalation.”

Fortunately, “the optimal breathing rhythm usually comes naturally,” says Arend. “It is dependent on the athlete, the intensity of the rowing, the tempo, etc.” It is only if a rower feels that their breathing is restricted at any point that Arend suggests taking a closer look to “analyse what type of breathing rhythm they use.”